Saturday, 5 November 2016

CURARE - by ALEXANDER VON HUMBOLDT

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Strychnos toxifera by Koehler 1887

PERSONAL NARRATIVE OF TRAVELS TO THE EQUINOCTIAL REGIONS OF AMERICA DURING THE YEARS 1799-1804

Esmeralda is the most celebrated spot on the Orinoco for the preparation of that active poison, which is employed in war, in the chase, and, singularly enough, as a remedy for gastric derangements. The poison of the ticunas of the Amazon, the upas-tieute of Java, and the curare of Guiana, are the most deleterious substances that are known. Raleigh, about the end of the sixteenth century, had heard of urari* as being a vegetable substance with which arrows were envenomed (* In Tamanac marana, in Maypure macuri.); yet no fixed notions of this poison had reached Europe. The missionaries Gumilla and Gili had not been able to penetrate into the country where the curare is manufactured. Gumilla asserts that this preparation was enveloped in great mystery; that its principal ingredient was furnished by a subterranean plant with a tuberous root, which never puts forth leaves, and which is called specially the root (raiz de si misma); that the venomous exhalations which arise from the manufacture are fatal to the lives of the old women who (being otherwise useless) are chosen to watch over this operation; finally, that these vegetable juices are never thought to be sufficiently concentrated till a few drops produce at a distance a repulsive action on the blood. An Indian wounds himself slightly; and a dart dipped in the liquid curare is held near the wound. If it make the blood return to the vessels without having been brought into contact with them, the poison is judged to be sufficiently concentrated.

When we arrived at Esmeralda, the greater part of the Indians were returning from an excursion which they had made to the east, beyond the Rio Padamo, to gather juvias, or the fruit of the bertholletia, and the liana which yields the curare. Their return was celebrated by a festival, which is called in the mission la fiesta de las juvias, and which resembles our harvest-homes and vintage-feasts. The women had prepared a quantity of fermented liquor; and during two days the Indians were in a state of intoxication. Among nations who attach great importance to the fruit of the palm, and of some other trees useful for the nourishment of man, the period when these fruits are gathered is marked by public rejoicings, and time is divided according to these festivals, which succeed one another in a course invariably regular. We were fortunate enough to find an old Indian more temperate than the rest, who was employed in preparing the curare poison from freshly-gathered plants. He was the chemist of the place. We found at his dwelling large earthen pots for boiling the vegetable juice, shallower vessels to favour the evaporation by a larger surface, and leaves of the plantain-tree rolled up in the shape of our filters, and used to filtrate the liquids, more or less loaded with fibrous matter. The greatest order and neatness prevailed in this hut, which was transformed into a chemical laboratory. The old Indian was known throughout the mission by the name of the poison-master (amo del curare). He had that self-sufficient air and tone of pedantry of which the pharmacopolists of Europe were formerly accused. "I know," said he, "that the whites have the secret of making soap, and manufacturing that black powder which has the defect of making a noise when used in killing animals. The curare, which we prepare from father to son, is superior to anything you can make down yonder (beyond sea). It is the juice of an herb which kills silently, without any one knowing whence the stroke comes."

This chemical operation, to which the old man attached so much importance, appeared to us extremely simple. The liana (bejuco) used at Esmeralda for the preparation of the poison, bears the same name as in the forests of Javita. It is the bejuco de Mavacure, which is gathered in abundance east of the mission, on the left bank of the Orinoco, beyond the Rio Amaguaca, in the mountainous and rocky tracts of Guanaya and Yumariquin. Although the bundles of bejuco which we found in the hut of the Indian were entirely bare of leaves, we had no doubt of their being produced by the same plant of the strychnos family (nearly allied to the rouhamon of Aublet) which we had examined in the forest of Pimichin.* (* I may here insert the description of the curare or bejuco de Mavacure, taken from a manuscript, yet unpublished, of my learned fellow-labourer M. Kunth, corresponding member of the Institute. "Ramuli lignosi, oppositi, ramulo altero abortivo, teretiusculi, fuscescenti-tomentosi, inter petiolos lineola pilosa notati, gemmula aut processu filiformi (pedunculo?) terminati. FOLIA opposita, bereviter petiolata, ovato-oblonga, acuminata, intergerrima, reticulato-triplinervia, nervo medio subtus prominente, membranacea, ciliata, utrinque glabra, nervo medio fuscescente-tomentoso, lacte viridia, subtus pallidiora, 1 1/2 to 2 1/2 pollices longa, 8 to 9 lineas lata. PETIOLI lineam longi, tomentosi, inarticulati.") The mavacure is employed fresh or dried indifferently during several weeks. The juice of the liana, when it has been recently gathered, is not regarded as poisonous; possibly it is so only when strongly concentrated. It is the bark and a part of the alburnum which contain this terrible poison. Branches of the mavacure four or five lines in diameter are scraped with a knife, and the bark that comes off is bruised, and reduced into very thin filaments on the stone employed for grinding cassava. The venomous juice being yellow, the whole fibrous mass takes that colour. It is thrown into a funnel nine inches high, with an opening four inches wide. This funnel was of all the instruments of the Indian laboratory that of which the poison-master seemed to be most proud. He asked us repeatedly if, por alla (out yonder, meaning in Europe) we had ever seen anything to be compared to this funnel (embudo). It was a leaf of the plantain-tree rolled up in the form of a cone, and placed within another stronger cone made of the leaves of the palm-tree. The whole of this apparatus was supported by slight frame-work made of the petioles and ribs of palm-leaves. A cold infusion is first prepared by pouring water on the fibrous matter which is the ground bark of the mavacure. A yellowish water filters during several hours, drop by drop, through the leafy funnel. This filtered water is the poisonous liquor, but it acquires strength only when concentrated by evaporation, like molasses, in a large earthen pot. The Indian from time to time invited us to taste the liquid; its taste, more or less bitter, decides when the concentration by fire has been carried sufficiently far. There is no danger in tasting it, the curare being deleterious only when it comes into immediate contact with the blood. The vapours, therefore, which are disengaged from the pans are not hurtful, notwithstanding all that has been asserted on this point by the missionaries of the Orinoco. Fontana, in his experiments on the poison of the ticuna of the Amazon, long since proved that the vapours arising from this poison, when thrown on burning charcoal, may be inhaled without danger and that the statement of La Condamine, that Indian women, when condemned to death, have been killed by the vapours of the poison of the ticuna, is incorrect.

The most concentrated juice of the mavacure is not thick enough to stick to the darts; and therefore, to give a body to the poison, another vegetable juice, extremely glutinous, drawn from a tree with large leaves, called kiracaguero, is poured into the concentrated infusion. As this tree grows at a great distance from Esmeralda, and was at that period as destitute of flowers and fruits as the bejuco de mavacure, we could not determine it botanically. I have several times mentioned that kind of fatality which withholds the most interesting plants from the examination of travellers, while thousands of others, of the chemical properties of which we are ignorant, are found loaded with flowers and fruits. In travelling rapidly, even within the tropics, where the flowering of the ligneous plants is of such long duration, scarcely one-eighth of the trees can be seen furnishing the essential parts of fructification. The chances of being able to determine, I do not say the family, but the genus and species, is consequently as one to eight; and it may be conceived that this unfavourable chance is felt most powerfully when it deprives us of the intimate knowledge of objects which afford a higher interest than that of descriptive botany.

At the instant when the glutinous juice of the kiracaguero-tree is poured into the venomous liquor well concentrated, and kept in a state of ebullition, it blackens, and coagulates into a mass of the consistence of tar, or of a thick syrup. This mass is the curare of commerce. When we hear the Indians say that the kiracaguero is as necessary as the bejuco do mavacure in the manufacture of the poison, we may be led into error by the supposition that the former also contains some deleterious principle, while it only serves (as the algarrobo, or any other gummy substance would do) to give more body to the concentrated juice of the curare. The change of colour which the mixture undergoes is owing to the decomposition of a hydruret of carbon; the hydrogen is burned, and the carbon is set free. The curare is sold in little calabashes; but its preparation being in the hands of a few families, and the quantity of poison attached to each dart being extremely small, the best curare, that of Esmeralda and Mandavaca, is sold at a very high price. This substance, when dried, resembles opium; but it strongly absorbs moisture when exposed to the air. Its taste is an agreeable bitter, and M. Bonpland and myself have often swallowed small portions of it. There is no danger in so doing, if it be certain that neither lips nor gums bleed. In experiments made by Mangili on the venom of the viper, one of his assistants swallowed all the poison that could be extracted from four large vipers of Italy, without being affected by it. The Indians consider the curare, taken internally, as an excellent stomachic. The same poison prepared by the Piraoas and Salives, though it has some celebrity, is not so much esteemed as that of Esmeralda. The process of this preparation appears to be everywhere nearly the same; but there is no proof that the different poisons sold by the same name at the Orinoco and the Amazon are identical, and derived from the same plants. Orfila, therefore, in his excellent work On Poisons, has very judiciously separated the wourali of Dutch Guiana, the curare of the Orinoco, the ticuna of the Amazon, and all those substances which have been too vaguely united under the name of American poisons. Possibly at some future day, one and the same alkaline principle, similar to morphine and strychnia, will be found in poisonous plants belonging to different genera.

At the Orinoco the curare de raiz (of the root) is distinguished from the curare de bejuco (of lianas, or of the bark of branches). We saw only the latter prepared; the former is weaker, and much less esteemed. At the river Amazon we learned to distinguish the poisons of the Ticuna, Yagua, Peva, and Xibaro Indians, which being all obtained from the same plant, perhaps differ only by a more or less careful preparation. The Ticuna poison, to which La Condamine has given so much celebrity in Europe, and which somewhat improperly begins to bear the name of ticuna, is extracted from a liana which grows in the island of Mormorote, on the Upper Maranon. This poison is employed partly by the Ticunas, who remain independent on the Spanish territory near the sources of the Yacarique; and partly by Indians of the same tribe, inhabiting the Portuguese mission of Loreto. The poisons we have just named differ totally from that of La Peca, and from the poison of Lamas and of Moyobamba. I enter into these details because the vestiges of plants which we were able to examine, proved to us (contrary to the common opinion) that the three poisons of the Ticunas, of La Peca, and of Moyobamba are not obtained from the same species, probably not even from congeneric plants. In proportion as the preparation of the curare is simple, that of the poison of Moyobamba is a long and complicated process. With the juice of the bejuco de ambihuasca, which is the principal ingredient, are mixed pimento, tobacco, barbasco (Jacquinia armillaris), sanango (Tabernae montana), and the milk of some other apocyneae. The fresh juice of the ambihuasca has a deleterious action when in contact with the blood; the juice of the mavacure is a mortal poison only when it is concentrated by fire; and ebullition deprives the juice of the root of Jatropha manihot (the manioc) of all its baneful qualities. In rubbing a long time between my fingers the liana which yields the potent poison of La Peca, when the weather was excessively hot, my hands were benumbed; and a person who was employed with me felt the same effects from this rapid absorption by the uninjured integuments.

I shall not here enter into any detail on the physiological properties of those poisons of the New World which kill with the same promptitude as the strychneae of Asia,* (* The nux vomica, the upas tieute, and the bean of St. Ignatius, Strychnos Ignatia.) but without producing vomiting when they are received into the stomach, and without denoting the approach of death by the violent excitement of the spinal marrow. Scarcely a fowl is eaten on the banks of the Orinoco which has not been killed with a poisoned arrow; and the missionaries allege that the flesh of animals is never so good as when this method is employed. Father Zea, who accompanied us, though ill of a tertian fever, every morning had the live fowls allotted for our food brought to his hammock together with an arrow, and he killed them himself; for he would not confide this operation, to which he attached great importance, to any other person. Large birds, a guan (pava de monte) for instance, or a curassao (alector), when wounded in the thigh, die in two or three minutes; but it is often ten or twelve minutes before life is extinct in a pig or a peccary. M. Bonpland found that the same poison, bought in different villages, varied much. We had procured at the river Amazon some real Ticuna poison which was less potent than any of the varieties of the curare of the Orinoco. Travellers, on arriving in the missions, frequently testify their apprehension on learning that the fowls, monkeys, guanas, and even the fish which they eat, have been killed with poisoned arrows. But these fears are groundless. Majendie has proved by his ingenious experiments on transfusion, that the blood of animals on which the bitter strychnos of India has produced a deleterious effect, has no fatal action on other animals. A dog received a considerable quantity of poisoned blood into his veins without any trace of irritation being perceived in the spinal marrow.

I placed the most active curare in contact with the crural nerves of a frog, without perceiving any sensible change in measuring the degree of irritability of the organs, by means of an arc formed of heterogeneous metals. Galvanic experiments succeeded upon birds, some minutes after I had killed them with a poisoned arrow. These observations are not uninteresting, when we recollect that a solution of the upas-poison poured upon the sciatic nerve, or insinuated into the texture of the nerve, produces also a sensible effect on the irritability of the organs by immediate contact with the medullary substance. The danger of the curare, as of most of the other strychneae (for we continue to believe that the mavacure belongs to a neighbouring family), results only from the action of the poison on the vascular system. At Maypures, a zambo descended from an Indian and a negro, prepared for M. Bonpland some of those poisoned arrows, that are shot from blowing-tubes to kill small monkeys or birds. He was a man of remarkable muscular strength. Having had the imprudence to rub the curare between his fingers after being slightly wounded, he fell on the ground seized with a vertigo, that lasted nearly half an hour. Happily the poison was of that diluted kind which is used for very small animals, that is, for those which it is believed can be recalled to life by putting muriate of soda into the wound. During our passage in returning from Esmeralda to Atures, I myself narrowly escaped an imminent danger. The curare, having imbibed the humidity of the air, had become fluid, and was spilt from an imperfectly closed jar upon our linen. The person who washed the linen had neglected to examine the inside of a stocking, which was filled with curare; and it was only on touching this glutinous matter with my hand, that I was warned not to draw on the poisoned stocking. The danger was so much the greater, as my feet at that time were bleeding from the wounds made by chegoes (Pulex penetrans), which had not been well extirpated. This circumstance may warn travellers of the caution requisite in the conveyance of poisons.

An interesting chemical and physiological investigation remains to be accomplished in Europe on the poisons of the New World, when, by more frequent communications, the curare de bejuco, the curare de raiz, and the various poisons of the Amazon, Guallaga, and Brazil, can be procured, without being confounded together, from the places where they are prepared. Since the discovery of prussic acid,* (* First obtained by Scheele in the year 1782. Gay-Lussac (to whom we are indebted for the complete analysis of this acid) observes that it can never become very dangerous to society, because its peculiar smell (that of bitter almonds) betrays its presence, and the facility with which it is decomposed makes it difficult to preserve.) and many other new substances eminently deleterious, the introduction of poisons prepared by savage nations is less feared in Europe; we cannot however appeal too strongly to the vigilance of those who keep such noxious substances in the midst of populous cities, the centres of civilization, misery, and depravity. Our botanical knowledge of the plants employed in making poison can be but very slowly acquired. Most of the Indians who make poisoned arrows, are totally ignorant of the nature of the venomous substances they use, and which they obtain from other people. A mysterious veil everywhere covers the history of poisons and of their antidotes. Their preparation among savages is the monopoly of the piaches, who are at once priests, jugglers, and physicians; it is only from the natives who are transplanted to the missions, that any certain notions can be acquired on matters so problematical. Ages elapsed before Europeans became acquainted through the investigation of M. Mutis, with the bejuco del guaco (Mikania guaco), which is the most powerful of all antidotes against the bite of serpents, and of which we were fortunate enough to give the first botanical description.

The opinion is very general in the missions that no cure is possible, if the curare be fresh, well concentrated, and have stayed long in the wound, to have entered freely into the circulation. Among the specifics employed on the banks of the Orinoco, and in the Indian Archipelago, the most celebrated is muriate of soda.* (* Oviedo, Sommario delle Indie Orientali, recommends sea-water as an antidote against vegetable poisons. The people in the missions never fail to assure European travellers, that they have no more to fear from arrows dipped in curare, if they have a little salt in their mouths, than from the electric shocks of the gymnoti, when chewing tobacco. Raleigh recommends as an antidote to the ourari (curare) the juice of garlick. [But later experiments have completely proved that if the poison has once fairly entered into combination with the blood there is no remedy, either for man or any of the inferior animals. The wourali and other poisons mentioned by Humboldt have, since the publication of this work, been carefully analysed by the first chemists of Europe, and experiments made on their symptoms and supposed remedies. Artificial inflation of the lungs was found the most successful, but in very few instances was any cure effected.]) The wound is rubbed with this salt, which is also taken internally. I had myself no direct and sufficiently convincing proof of the action of this specific; and the experiments of Delille and Majendie rather tend to disprove its efficacy. On the banks of the Amazon, the preference among the antidotes is given to sugar; and muriate of soda being a substance almost unknown to the Indians of the forests, it is probable that the honey of bees, and that farinaceous sugar which oozes from plantains dried in the sun, were anciently employed throughout Guiana. In vain have ammonia and eau-de-luce been tried against the curare; it is now known that these specifics are uncertain, even when applied to wounds caused by the bite of serpents. Sir Everard Home has shown that a cure is often attributed to a remedy, when it is owing only to the slightness of the wound, and to a very circumscribed action of the poison. Animals may with impunity be wounded with poisoned arrows, if the wound be well laid open, and the point imbued with poison be withdrawn immediately after the wound is made. If salt or sugar be employed in these cases, people are tempted to regard them as excellent specifics. Indians, who had been wounded in battle by weapons dipped in the curare, described to us the symptoms they experienced, which were entirely similar to those observed in the bite of serpents. The wounded person feels congestion in the head, vertigo, and nausea. He is tormented by a raging thirst, and numbness pervades all the parts that are near the wound.

The old Indian, who was called the poison-master, seemed flattered by the interest we took in his chemical processes. He found us sufficiently intelligent to lead him to the belief that we knew how to make soap, an art which, next to the preparation of curare, appeared to him one of the finest of human inventions. When the liquid poison had been poured into the vessels prepared for their reception, we accompanied the Indian to the festival of the juvias. The harvest of juvias, or fruits of the Bertholletia excelsa,* (* The Brazil-nut.) was celebrated by dancing, and by excesses of wild intoxication. The hut where the natives were assembled, displayed during several days a very singular aspect. There was neither table nor bench; but large roasted monkeys, blackened by smoke, were ranged in regular order against the wall. These were the marimondes (Ateles belzebuth), and those bearded monkeys called capuchins, which must not be confounded with the weeper, or sai (Simia capucina of Buffon). The manner of roasting these anthropomorphous animals contributes to render their appearance extremely disagreeable in the eyes of civilized man. A little grating or lattice of very hard wood is formed, and raised one foot from the ground. The monkey is skinned, and bent into a sitting posture; the head generally resting on the arms, which are meagre and long; but sometimes these are crossed behind the back. When it is tied on the grating, a very clear fire is kindled below. The monkey, enveloped in smoke and flame, is broiled and blackened at the same time. On seeing the natives devour the arm or leg of a roasted monkey, it is difficult not to believe that this habit of eating animals so closely resembling man in their physical organization, has, to a certain degree, contributed to diminish the horror of cannibalism among these people. Roasted monkeys, particularly those which have very round heads, display a hideous resemblance to a child; and consequently Europeans who are obliged to feed on them prefer separating the head and the hands, and serve up only the rest of the animal at their tables. The flesh of monkeys is so lean and dry, that M. Bonpland has preserved in his collections at Paris an arm and hand, which had been broiled over the fire at Esmeralda; and no smell has arisen from them after the lapse of a great number of years.

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